Adds specs for prepareTokens

Minor cleanup the prepareTokens method
and adds additional specs

ee/app/assets/javascripts/analytics/cycle_analytics/components/filter_bar.vue

@@ -6,27 +6,22 @@ import MilestoneToken from '../../shared/components/tokens/milestone_token.vue';
 import LabelToken from '../../shared/components/tokens/label_token.vue';
 import UserToken from '../../shared/components/tokens/user_token.vue';
 
-const prepareTokens = ({
-  selectedMilestone = null,
-  selectedAuthor = null,
-  selectedAssignees = [],
-  selectedLabels,
-}) => {
-  const authorToken = selectedAuthor ? { type: 'author', value: { data: selectedAuthor } } : null;
-  const milestoneToken = selectedMilestone
-    ? { type: 'milestone', value: { data: selectedMilestone } }
-    : null;
-  const assigneeTokens = selectedAssignees.length
-    ? selectedAssignees.map(data => ({ type: 'assignees', value: { data } }))
+export const prepareTokens = ({
+  milestone = null,
+  author = null,
+  assignees = [],
+  labels = [],
+} = {}) => {
+  const authorToken = author ? [{ type: 'author', value: { data: author } }] : [];
+  const milestoneToken = milestone ? [{ type: 'milestone', value: { data: milestone } }] : [];
+  const assigneeTokens = assignees?.length
+    ? assignees.map(data => ({ type: 'assignees', value: { data } }))
     : [];
-  const labelTokens = selectedLabels.length
-    ? selectedLabels.map(data => ({ type: 'labels', value: { data } }))
+  const labelTokens = labels?.length
+    ? labels.map(data => ({ type: 'labels', value: { data } }))
     : [];
 
-  let initTokens = [...assigneeTokens, ...labelTokens];
-  if (authorToken) initTokens = [...initTokens, authorToken];
-  if (milestoneToken) initTokens = [...initTokens, milestoneToken];
-  return initTokens;
+  return [...authorToken, ...milestoneToken, ...assigneeTokens, ...labelTokens];
 };
 
 export default {
@@ -111,7 +106,13 @@ export default {
   methods: {
     ...mapActions('filters', ['setFilters']),
     initializeTokens() {
-      const preparedTokens = prepareTokens(this.initialTokens);
+      const {
+        selectedMilestone: milestone = null,
+        selectedAuthor: author = null,
+        selectedAssignees: assignees = [],
+        selectedLabels: labels = [],
+      } = this.initialTokens;
+      const preparedTokens = prepareTokens({ milestone, author, assignees, labels });
       this.value = preparedTokens;
     },
     processFilters(filters) {

ee/spec/frontend/analytics/cycle_analytics/components/filter_bar_spec.js

 import { createLocalVue, shallowMount } from '@vue/test-utils';
 import Vuex from 'vuex';
 import { GlFilteredSearch } from '@gitlab/ui';
-import FilterBar from 'ee/analytics/cycle_analytics/components/filter_bar.vue';
+import FilterBar, { prepareTokens } from 'ee/analytics/cycle_analytics/components/filter_bar.vue';
 import initialFiltersState from 'ee/analytics/cycle_analytics/store/modules/filters/state';
 import { filterMilestones, filterLabels } from '../mock_data';
 
@@ -176,4 +176,27 @@ describe('Filter bar', () => {
       );
     });
   });
+
+  describe('prepareTokens', () => {
+    describe('with empty data', () => {
+      it('returns an empty array', () => {
+        expect(prepareTokens()).toEqual([]);
+        expect(prepareTokens({})).toEqual([]);
+        expect(prepareTokens({ milestone: null, author: null, assignees: [], labels: [] })).toEqual(
+          [],
+        );
+      });
+    });
+
+    it.each`
+      token          | value                     | result
+      ${'milestone'} | ${'v1.0'}                 | ${[{ type: 'milestone', value: { data: 'v1.0' } }]}
+      ${'author'}    | ${'mr.popo'}              | ${[{ type: 'author', value: { data: 'mr.popo' } }]}
+      ${'labels'}    | ${['z-fighters']}         | ${[{ type: 'labels', value: { data: 'z-fighters' } }]}
+      ${'assignees'} | ${['krillin', 'piccolo']} | ${[{ type: 'assignees', value: { data: 'krillin' } }, { type: 'assignees', value: { data: 'piccolo' } }]}
+    `('with $token=$value sets the $token key', ({ token, value, result }) => {
+      const res = prepareTokens({ [token]: value });
+      expect(res).toEqual(result);
+    });
+  });
 });